The Washington Post reported that charges have been drawn up for Mr Assange but it is not clear on what grounds.

The ongoing investigation into ties between Russia and the 2016 presidential campaign has suggested that WikiLeaks was used by Russian intelligence to distribute hacked material.

Mr Assange's lawyer Barry Pollack said, "The news that criminal charges have apparently been filed against Mr Assange is even more troubling than the haphazard manner in which that information has been revealed.

"The government bringing criminal charges against someone for publishing truthful information is a dangerous path for a democracy to take."